Capsules of pathogenic enteric bacteria are virulence factors because they
a. capture iron from hemoglobin and store it in the bacteria
b. release hemolysins that destroy red blood cells
c. produce fimbriae that enable the bacteria to attach to human cells
d. protect the bacteria from phagocytosis and from some antibodies

Verified step by step guidance

1. Identify the role of capsules in bacteria, particularly in pathogenic enteric bacteria.
2. Understand that capsules are a type of glycocalyx that surrounds the cell wall of some bacteria.
3. Recognize that one of the primary functions of a capsule is to protect bacteria from the host's immune system.
4. Consider how capsules can prevent phagocytosis by making it difficult for immune cells to engulf the bacteria.
5. Evaluate the options given and determine which one aligns with the protective role of capsules against the immune system.

Key Concepts

Virulence Factors

Virulence factors are molecules produced by pathogens that contribute to their ability to cause disease. These factors can enhance the pathogen's invasiveness, facilitate adherence to host tissues, or evade the host's immune response. Understanding virulence factors is crucial for comprehending how certain bacteria can establish infections and lead to disease.

Capsules in Bacteria

Capsules are protective outer layers found in some bacteria, composed of polysaccharides or proteins. They play a significant role in the virulence of pathogenic bacteria by providing a barrier against phagocytosis, which is the process by which immune cells engulf and destroy pathogens. This protection allows bacteria to survive longer in the host and increases their chances of causing disease.

Phagocytosis

Phagocytosis is a key immune response where specialized cells, such as macrophages and neutrophils, engulf and digest pathogens. This process is essential for the innate immune system to eliminate infections. Understanding phagocytosis helps explain how certain bacterial structures, like capsules, can hinder the immune response and contribute to the persistence of infections.